Method for transmitting and receiving audio in Mosaic EPG service

ABSTRACT

Disclosed is a method for transmitting and receiving audio in a Mosaic electronic program guide (EPG) service. A digital broadcast transmitting side mixes stereo audio signals corresponding to each sub-picture within a Mosaic EPG picture and encodes mono audio signals corresponding to odd and even-numbered sub-pictures into one stereo audio signal. The digital broadcast transmitting side transmits the stereo audio signal based on a result of the encoding through the Mosaic EPG service. Therefore, the method can efficiently transmit audio of a sub-picture within the Mosaic EPG picture, and can minimize bandwidth necessary for transmitting audio of sub-pictures within the Mosaic EPG picture. A user can confirm and select a desired broadcast program while listening to audio corresponding to a sub-picture within the Mosaic EPG picture, thereby conveniently using the desired broadcast program.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method for transmitting and receivingaudio in a Mosaic electronic program guide (EPG) service, and moreparticularly to a method for efficiently transmitting and receivingaudio linked to each sub-picture provided through a Mosaic electronicprogram guide (EPG) service.

2. Description of the Related Art

Recently, an electronic program guide (EPG) service is beingcommercialized to provide various types of broadcast programinformation. Moreover, a digital broadcast receiver such as a set-topbox (STB) receives EPG information and outputs the received EPGinformation through a screen of an external display unit such as atelevision (TV), such that a user can easily search for desiredbroadcast program information.

The Mosaic EPG service is being carried out in order for the user toeasily search for and select various broadcast programs provided throughdifferent broadcast services. The Mosaic EPG service will be describedin detail.

FIG. 1 is a block diagram illustrating transmitting and receiving sidesfor transmitting and receiving a conventional Mosaic electronic programguide (EPG) service. A transmitting side 100 comprises a Mosaic screengenerator 10, an encoder 11, a multiplexer (MUX) & modulator 12, anup-linker 13 and a Mosaic information generator 14.

The Mosaic screen generator 10 generates a Mosaic screen so that variousbroadcast programs BS 1 to BS k provided through different broadcastservices can be displayed as small-sized sub-pictures within one screen.The encoder 11 encodes the Mosaic screen into a Moving Picture ExpertsGroup (MPEG) data stream appropriate for digital broadcast. Moreover,the MUX & modulator 12 multiplexes and modulates Mosaic informationgenerated by the Mosaic information generator 14 and the MPEG datastream based on the encoding, and outputs a result of the multiplexingand modulation to a broadcast satellite 200 via the up-linker 13.

A digital broadcast receiver 400 such as a set-top box (STB) outputs theMosaic EPG picture received from the broadcast satellite 200 through ascreen of the TV 500.

For example, the Mosaic EPG picture can include 1^(st) to 9^(th)sub-pictures 1 to 9 corresponding to 1^(st) to 9^(th) programs 1 to 9provided through different broadcast services within an identical screenas shown in FIG. 2.

When a selection button provided in a remote controller (not shown) oretc. is clicked in a state where the user places a cursor on onearbitrary sub-picture included in the Mosaic EPG picture, for example,in a state where the cursor is placed on the 1^(st) sub-picture, thedigital broadcast receiver 400 refers to the Mosaic information providedthrough the Mosaic EPG service, selects a broadcast service providingthe 1^(st) broadcast program corresponding to the 1^(st) sub-picture,and outputs the 1^(st) broadcast program received through the broadcastservice to a main picture screen.

Thus, the user of the digital broadcast receiver can simultaneouslysearch for various broadcast programs provided by different broadcastservices through the Mosaic EPG picture, and can easily select ordesignate one arbitrary broadcast service.

The user of the digital broadcast receiver visually confirms a broadcastprogram through a sub-picture included in the Mosaic EPG picture andthen selects a desired broadcast program according to a result of theconfirmation. Moreover, the user may desire to listen to audio of thebroadcast program corresponding to each sub-picture when selecting thedesired broadcast program. That is, it is necessary that audio of eachof the broadcast programs corresponding to the sub-pictures included inthe Mosaic EPG picture be provided through the Mosaic EPG service.However, a method for efficiently providing audio of the broadcastprograms in the Mosaic EPG picture is not provided.

SUMMARY OF THE INVENTION

Therefore, the present invention has been made in view of the aboveproblems, and it is one object of the present invention to provide amethod for efficiently transmitting and receiving audio linked to eachsub-picture in a Mosaic electronic program guide (EPG) service.

It is another object of the present invention to provide a method forallowing a user to easily select a desired broadcast program while he orshe listens to audio linked to each sub-picture in a Mosaic electronicprogram guide (EPG) service.

In accordance with one aspect of the present invention, the above andother objects can be accomplished by the provision of a method fortransmitting audio in a Mosaic electronic program guide (EPG) service,comprising; combining a predetermined number of sub-pictures within aMosaic EPG picture in one unit and encoding audio signals of broadcastprograms corresponding to the predetermined number of sub-pictures intoone audio signal; and transmitting the one audio signal through theMosaic EPG service. Here, when an audio system of the broadcast programsis a 2-channel stereo system, audio of an odd-numbered sub-picture andaudio of an even-numbered sub-picture are encoded into one piece of2-channel audio data. A unique audio packet identification (ID) isadditionally recorded on a header of the audio data. In order that audiodata corresponding to a selected sub-picture can be searched for,navigation information is added to program map table (PMT) informationin which the unique audio packet ID is mapped to each sub-picture. Thenavigation information is transmitted through the Mosaic EPG service.

In accordance with another aspect of the present invention, the aboveand other objects can be accomplished by the provision of a method forreceiving audio in a Mosaic electronic program guide (EPG) service,comprising; confirming an audio packet identification (ID) of abroadcast program corresponding to one arbitrary sub-picture on which acursor is placed within a Mosaic EPG picture; selectively extractingonly audio data on which the confirmed audio packet ID is additionallyrecorded; and decoding the extracted audio data, separating partialaudio data corresponding to the sub-picture from the decoded audio dataand outputting the separated partial audio data.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and other advantages of thepresent invention will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a block diagram illustrating transmitting and receiving sidesfor transmitting and receiving a conventional Mosaic electronic programguide (EPG) service;

FIG. 2 shows an example of selecting or designating one arbitrarysub-picture from a conventional Mosaic EPG picture;

FIG. 3 is a block diagram illustrating the configuration of atransmitting side to which a method for transmitting audio in the MosaicEPG service is applied in accordance with an embodiment of the presentinvention;

FIG. 4 shows a process for transmitting audio in the Mosaic EPG servicein accordance with the present invention;

FIG. 5 is a block diagram illustrating the configuration of a receivingside to which a method for receiving audio in the Mosaic EPG service isapplied in accordance with the present invention; and

FIG. 6 shows a process for receiving audio in the Mosaic EPG service inaccordance with the present invention.

DETAILED DESCRIPTION OF PREFFERRED EMBODIMENTS

Hereinafter, a method for transmitting and receiving audio in a Mosaicelectronic program guide (EPG) service in accordance with preferredembodiments of the present invention will be described in detail withreference to the annexed drawings.

First, the method for transmitting audio in the Mosaic EPG service inaccordance with the present invention is applied to a digital broadcasttransmitting side that provides the Mosaic EPG service. As shown in FIG.3, the transmitting side can comprise a Mosaic screen generator 10, avideo encoder 11, a multiplexer (MUX) & modulator 12, an up-linker 13and a Mosaic information generator 14. The transmitting side can furthercomprise an audio encoder 15 and a plurality of mixers 16 ₁ to 16 _(k).

As described with reference to FIG. 1, the Mosaic screen generator 10generates a Mosaic screen so that various broadcast programs BS 1 to BSk currently being broadcast or to be broadcast through differentbroadcast services can be displayed as small-sized sub-pictures withinone screen. The video encoder 11 encodes the Mosaic screen into a videodata stream appropriate for digital broadcast.

Moreover, each of the mixers 16 ₁ to 16 _(k) mixes stereo audio signalsof left and right channels corresponding to each sub-picture to generateand output a mono audio signal. For example, the 1^(st) mixer 16 ₁ mixes1^(st) stereo audio signals A₁ ^(L) and A₁ ^(R) of the two left andright channels corresponding to the 1^(st) sub-picture, and generatesand outputs a 1^(st) mono audio signal A₁. The 2^(nd) mixer 16 ₂ mixes2^(nd) stereo audio signals A₂ ^(L) and A₂ ^(R) of the two channelscorresponding to the 2^(nd) sub-picture, and generates and outputs a2^(nd) mono audio signal A₂.

The audio encoder 15 combines and encodes the 1^(st) mono audio signalA₁ and the 2^(nd) mono audio signal A₂ to generate a left-channel audiosignal A_(1/2) ^(L) and a right-channel audio signal A_(1/2) ^(R)corresponding to the 1^(st) and 2^(nd) sub-pictures as shown in FIG. 4.The mono audio signal A₁, A₃ or etc. corresponding to an odd-numberedsub-picture, i.e., a (2k−1)^(th) sub-picture, and the mono audio signalA₂, A₄ or etc. corresponding to an even-numbered sub-picture, i.e., a(2k)^(th) sub-picture, are encoded into a left-channel audio signalA_(2k·1/2k) ^(L) and a right-channel audio signal A_(2k·1/2k) ^(R)corresponding to the (2k−1)^(th) and (2k)^(th) sub-pictures.

The MUX & modulator 12 mixes and modulates an audio data stream based onan encoding operation by the audio encoder 15, a video data stream basedon an encoding operation by the video encoder 11, and the Mosaicinformation generated by the Mosaic information generator 14. The MUX &modulator 12 transmits a result of the mixing and modulation to thebroadcast satellite 200 via the up-linker 13. At this point, a uniqueaudio packet identification (A_PID) corresponding to the (2k−1)^(th) and(2k)^(th) sub-pictures is additionally recorded on a packet header ofthe audio data stream.

For example, a unique identification value “PID_A_(1/2)” is added to theleft-channel audio signal A_(1/2) ^(L) and the right-channel audiosignal A_(1/2) ^(R) corresponding to the 1^(st) and 2^(nd) sub-pictures.A unique identification value “PID_A_(3/4)” is added to the left-channelaudio signal A_(3/4) ^(L) and the right-channel audio signal A_(3/4)^(R) corresponding to the 3^(rd) and 4^(th) sub-pictures.

Program map table (PMT) information of service information (SI) sentthrough the Mosaic EPG service includes an audio packet ID correspondingto each sub-picture as navigation information so that audio datacorresponding to each sub picture can be searched for. That is, theaudio packet ID of audio data containing audio linked to eachsub-picture is included as the navigation information.

A method for receiving audio in the Mosaic EPG service in accordancewith the present invention can be applied to the digital broadcastreceiver such as the STB. As shown in FIG. 5, the digital broadcastreceiver (or STB) 400 comprises: a tuner 40 for tuning a digitalbroadcast channel; a de-multiplexer (DEMUX) 41 for parsing a MovingPicture Experts Group (MPEG) transport stream received through onearbitrary service of broadcast services multiplexed into the broadcastchannel and producing audio, video and data; an audio buffer 42 fortemporarily storing the audio; a video buffer 43 for temporarily storingthe video; a data buffer 44 for temporarily storing the data; and anMPEG decoder 45 for decoding the temporarily stored audio, video anddata and recovering original audio and video signals.

The digital broadcast receiver 400 further comprises: an on screendisplay (OSD) generator 47 for superimposing and displaying a cursor ona Mosaic EPG picture and outputting a user key input window or an OSDimage of a user selection menu; a controller (or microcomputer) 46 forcontrolling operations of the respective components; and a memory 48 forstoring data necessary for controlling the operations of the respectivecomponents. The memory 48 stores service information (SI) such asprogram map table (PMT) information provided through the Mosaic EPGservice.

As shown in FIG. 6, the MPEG decoder 45 comprises a packetidentification (PID) filter 450, an audio decoder 451 and a divider 452.The PID filter 450 selectively outputs only audio data on which aspecific PID is additionally recorded, from the audio data streaminputted through the audio buffer 43.

For example, when the user places the cursor on the 1^(st) sub-pictureincluded and displayed within the Mosaic EPG picture as described withreference to FIG. 2, the controller 46 searches for the PMT informationstored in the memory 48, confirms an audio PID “PID_A_(1/2)”corresponding to the 1^(st) sub-picture on which the current cursor isplaced, and controls operation of the PID filter 450.

The PID filter 450 selectively outputs only audio data on which the PIDis additionally recorded, from an audio data stream inputted through theaudio buffer 42. Thus, the audio decoder 451 selectively receives theaudio data on which the PID “PID_A_(1/2)” is additionally recorded, thatis, only stereo audio data A_(1/2) ^(L) and A_(1/2) ^(R) of left andright channels corresponding to the 1^(st) and 2^(nd) sub-pictures.

Because the 1^(st) sub-picture on which the cursor is placed is the(2k−1)^(th) sub-picture, the controller 46 carries out a controloperation so that left-channel audio data A_(1/2) ^(L) corresponding tothe odd-numbered sub-picture can be decoded among the stereo audio dataA_(1/2) ^(L) and A_(1/2) ^(R) of the left and right channels inputtedinto the audio decoder 451, and a result of the decoding can beoutputted.

The divider 452 amplifies the inputted left-channel audio data A_(1/2)^(L) to a predetermined level after the above-described selection anddecoding process, divides a result of the amplification by 2, andoutputs the stereo audio signals (A_(1/2) ^(L))/2 of the left and rightchannels, such that audio signals A₁ ^(L′) and A₁ ^(R′) of the left andright channels corresponding to the 1^(st) sub-picture on which thecursor is placed are outputted.

Thus, the user can listen to audio corresponding to a sub-picture onwhich the cursor is placed within the Mosaic EPG picture. Moreover, thedigital broadcast transmitting side providing the Mosaic EPG servicemixes stereo audio signals corresponding to one sub-picture into a monoaudio signal, encodes the mono audio signal of the one sub-picture withanother mono audio signal of another sub-picture, and transmits a resultof the encoding, such that bandwidth necessary for the audiotransmission can be minimized.

When audio of a broadcast program has at least two channels based on a5.1 channel AC3 system rather than the stereo system, broadcast programaudio signals corresponding to the number of audio channels can beencoded into one audio signal. For example, where an audio system is the5.1 channel AC3 system, a mono audio signal based on each of the 5 or 6sub-pictures is generated and 5 or 6 audio signals are encoded into a5.1 channel, and a result of the encoding can be transmitted.

Moreover, when mono audio signals based on respective sub-pictures aregenerated, one arbitrary channel can be selected without mixingrespective channel audio signals to generate a mono audio signal.

As apparent from the above description, the present invention canefficiently transmit audio of a sub-picture within a Mosaic electronicprogram guide (EPG) picture.

Moreover, the present invention can minimize bandwidth necessary fortransmitting audio of sub-pictures within the Mosaic EPG picture.

In accordance with the present invention, the user can confirm andselect a desired broadcast program while listening to audiocorresponding to a sub-picture within the Mosaic EPG picture, therebyconveniently using the desired broadcast program.

Although the preferred embodiments of the present invention have beendisclosed for illustrative purposes, those skilled in the art willappreciate that various modifications, additions and substitutions arepossible, without departing from the scope of the invention.

1. A method for transmitting audio in a Mosaic electronic program guide(EPG) service, comprising; combining a predetermined number ofsub-pictures within a Mosaic EPG picture in one unit and encoding audiosignals of broadcast programs corresponding to the predetermined numberof sub-pictures into one audio signal; and transmitting the one audiosignal through the Mosaic EPG service.
 2. The method of claim 1, whereinthe predetermined number is determined by an audio system of thebroadcast programs corresponding to the sub-pictures.
 3. The method ofclaim 2, wherein the predetermined number is 2 when the audio system ofthe broadcast programs is a 2-channel stereo system, and wherein thepredetermined number is 5 or 6 when the audio system of the broadcastprograms is a 5.1 channel AC3 system.
 4. The method of claim 1, whereinthe encoding comprises: selecting one channel from audio signals of eachof the broadcast programs corresponding to the sub-pictures andoutputting a mono audio signal based on the selected channel; andencoding the output mono audio signals into one audio signal.
 5. Themethod of claim 1, wherein the encoding comprises: mixing audio signalsof each of the broadcast programs corresponding to the sub-pictures andgenerating a mono audio signal based on a result of the mixing; andencoding the generated mono audio signals into one audio signal.
 6. Themethod of claim 5, wherein a mono audio signal corresponding to anodd-numbered sub-picture and a mono audio signal corresponding to aneven-numbered sub-picture among the mono audio signals are encoded intoone 2-channel stereo audio signal based on the odd and even-numberedsub-pictures when an audio system of the broadcast programscorresponding to the sub-pictures is a 2-channel stereo system.
 7. Themethod of claim 1, wherein the encoding further comprises: additionallyrecording a unique audio packet identification (ID) based on a unit ofsub-pictures corresponding to audio data on a packet header of the audiodata.
 8. The method of claim 7, wherein the transmitting furthercomprises: additionally transmitting program map table (PMT) informationincluding navigation information in which the unique audio packet ID ismapped to each sub-picture, through the Mosaic EPG service.
 9. A methodfor receiving audio in a Mosaic electronic program guide (EPG) service,comprising; confirming an audio packet identification (ID) of abroadcast program corresponding to one arbitrary sub-picture on which acursor is placed within a Mosaic EPG picture; selectively extractingonly audio data on which the confirmed audio packet ID is additionallyrecorded; and decoding the extracted audio data, separating partialaudio data corresponding to the sub-picture from the decoded audio dataand outputting the separated partial audio data.
 10. The method of claim9, wherein the confirming comprises: referring to program map table(PMT) information transmitted through the Mosaic EPG service; andconfirming the audio packet ID of the broadcast program corresponding tothe sub-picture.
 11. The method of claim 9, wherein the separatingcomprises: separating the partial audio data corresponding to thesub-picture from the decoded audio data according to a value based onorder of the sub-picture on which the cursor is placed within the MosaicEPG picture and an audio system of the broadcast program.
 12. The methodof claim 11, wherein the separating comprises: when the audio system ofthe broadcast program is a 2-channel stereo system, separatingleft-channel audio data from the decoded audio data to output theseparated audio data, if the sub-picture is an odd-numbered sub-picture;and separating right-channel audio data from the decoded audio data tooutput the separated audio data if the sub-picture is an even-numberedsub-picture.